[PYTHON] Heroku deployment of the first Django app that beginners are addicted to

Due to various errands, I decided to deploy the locally made Django app to Heroku, but it took a long time, so as a memorandum.

environment

• Windows10
• Django 1.11.x
• python2.7.x

What is Django

(I think you know it when you read this article ...) Django seems to be a web framework that runs on Python2 and 3 ... It's "likely" because I'm not familiar with web frameworks. If you are interested, please refer to the official document ...?

Reference: Django documentation

What is deployment

Moving what was made in the local environment to the actual production environment ... Maybe. Web apps like Django weren't as easy as just uploading a website ... Below, I'll spell out the general flow of this deployment.

Prerequisites

If you haven't mastered Django yet, there was a nice article here, so learn from here ...! Explanation of Python Web application (Django) in an easy-to-understand manner even for beginners Master Django fastest

--General network environment (because you upload files) --Django app completed (using sqlite3 database) (virtualenv used) --CMD (command prompt) can be used --git installed --Heroku account owned

Deploy

The author who made the first web application using Django. It's slimy, it's moving, it's DB, it's moving One day, one day, it's finally time to move it online ... (story style)

Initial situation

DjangoApp/ 　├ env/ (virtualenv) 　├ manage.py 　├ db.sqlite3 ├ Django App / (the one from the beginning) 　│　├ wsgi.py 　│　└ setting.py └ App / (application body)

Eve of deployment

When I investigated what was necessary when deploying, "I put db.sqlite3 (sqlite database body), * .pyc, and env / and below in .gitignore". I made .gitignore obediently, deleted the cache with "git rm -r --cached." And committed

Reference: Reflect the settings of [Qiita] .gitignore

The situation after the night before

DjangoApp/ 　├ env/ 　├ manage.py 　├ db.sqlite3 　├ DjangoApp/ 　│　├ wsgi.py 　│　└ setting.py 　├ App/ 　└ .gitignore (New)

Ready to deploy

When uploading a file to Heroku, it seems that three kinds of sacred treasures "Procfile (without extension)" "requirements.txt" "runtime.txt" are required, so I will start creating

Procfile It tells Heroku that "This app should be launched like this! ☆" For the time being, I decided to write it exactly as it was written by various people.

Procfile

web: gunicorn DjangoApp.wsgi --log-file -

The Django App part describes your application name. And it seems that I have to install this "gunicorn" and so on in virtualenv later ... Mmm, it takes a lot of time and effort ...

requirements.txt You need to contact Heroku with the modules needed to run this application. Requirements.txt is used for that. (maybe) This is easy. After starting virtualenv with the command

CMD

pip freeze > requirements.txt 

And it is sufficient. You should have a file like the one below.

requirements.txt

Django==1.11.1
virtualenv==15.1.0

runtime.txt It seems to tell Heroku the version of python you are using now ... (I'm not sure)

CMD

python-2.7.x

The 2.7.x part is the version of Python installed on your computer.

After creating the three sacred treasures

DjangoApp/ 　├ env/ 　├ manage.py 　├ db.sqlite3 　├ DjangoApp/ 　│　├ wsgi.py 　│　└ setting.py 　├ App/ 　├ requirements.txt (New) 　├ runtime.txt (New) 　├ Procfile (New) 　└ .gitignore

Install Django-toolbelt

After investigating, it seems that various additional modules are required for deployment ... The above gunicorn, djando-static for handling static files, dj_database_url for handling databases, etc ... I think it is troublesome to handle each one. When I was there, I found an ally who could put these together! It's django-toolbelt ...!

CMD

pip install django-toolbelt

Install toolbelt as. All the necessary modules are available ...!

...... If you are a smart person, you should notice "this guy (laughs)" ... Yes, the module installed by toolbelt at this time is not written in requirements.txt ... I did not notice this for more than half a day Also spent time ... Correctly, let's update pip freeze again at this timing and update requirements.txt! !!

requirements.txt after installing toolbelt

requirements.txt

dj-database-url==0.4.2
dj-static==0.0.6
Django==1.11.1
django-toolbelt==0.0.1
gunicorn==19.7.1
psycopg2==2.7.3
pytz==2017.2
static3==0.7.0
virtualenv==15.1.0

It's still going on! Ready to deploy!

Next is the story around the database.

From what I hear, it seems that the sqlite3 database cannot be used on Heroku (I wonder if it can be installed ...?) Therefore, it is necessary to use (?) Postgres that is installed as standard on Heroku ...

…… And the dj-database-url for that! Open setting.py and find the following part.

setting.py

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}

Rewrite the description about this DB as follows

setting.py

if "COMPUTER-NAME" in hostname:
    #Debug environment
    # DEBUG = True //I also switched the debug mode here
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
        }
    }
    ALLOWED_HOSTS = [] #I'm not sure, but this seems to be important too
else:
    #Production environment
    # DEBUG = False
    import dj_database_url
    db_from_env = dj_database_url.config()
    DATABASES = {
        'default': dj_database_url.config()
    }
    ALLOWED_HOSTS = ['*']

This will use sqlite3 in your local environment and Postgres in your Heroku environment. (Likely) COMPUTER-NAME is the name of your device. (I saw that I should write local, but it didn't work in my environment ...) Also, if you (almost certainly) get angry with "I'm afraid you don't have a hostname!", Add the following to the beginning of setting.py.

setting.py

.
from socket import gethostname
hostname = gethostname()
.

I don't really understand wsgi

It's time to touch wsgi.py, which I haven't touched in the local environment ...! I think it's okay just to play with it a little like the following

setting.py

import os
from dj_static import Cling
from django.core.wsgi import get_wsgi_application

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "DjangoApp.settings")
application = Cling(get_wsgi_application())

Django App has its own project name. …… After all, what was wsgi.py (Sorega Karanai)

Final situation

DjangoApp/ 　├ env/ 　├ manage.py 　├ db.sqlite3 　├ DjangoApp/ 　│　├ wsgi.py (modified) 　│　└ setting.py (modified) 　├ App/ 　├ requirements.txt 　├ runtime.txt 　├ Procfile 　└ .gitignore

Deploy now! Aim for Heroku!

Now that we're ready, launch CMD and head to Heroku!

CMD

git add .
git commit -am "Launching now!"

heroku login
> Enter your Heroku credentials.
> Email: [email protected]
> Password (hidden):
> Logged in as [email protected]

heroku create NAME
> https://NAME.herokuapp.com/ | https://git.heroku.com/NAME.git

git push heroku master
>Something long

heroku run python manage.py migrate
>The usual migrate command flows

heroku open

The final Heroku open will open the application for you. (In my case, it was the first Application Error ...) That's it! The rest is operation! !! Thank you for your hard work! !! !! (tired

Impressions

It's hard to write an impression about this, but it was so difficult for beginners to think, "What a detour ... Can't you make it smarter?" ... (´; ω; `) In particular, there are few references for the latest (ver1.11) ... After all, I was reading the official English document (laughs). Spread, Django's circle!

Unresolved bugs

Breaking management site

Deployed to Heroku safely ... I thought, but the management site ...

It's broken ... (´ ・ ω ・ `) For some reason, it doesn't read CSS ... I added the following to setting.py to handle static files, but ... no ...!

setting.py

STATIC_URL = '/static/'

# Static asset configuration
STATIC_ROOT = 'staticfiles'

STATICFILES_DIRS = (
    os.path.join(BASE_DIR, 'static'),
)

...... Well, I will fix it patiently!